This invention pertains to the art of selectively dispensing or feeding a layered mask or tape. The invention finds particular application in the painting industry for dispensing a blending tape which defines a painting mask and will be described with particular reference thereto. However, it will be appreciated that the invention has broader applications and may be adapted to use in other environments.
In the painting industry, it is often desired to spray paint only a portion of a product or workpiece with one color or tone. Frequently, the workpiece is painted with the one color or tone on one side of a demarcation zone and with another color or tone on the other side of the demarcation zone. This type of two-tone painting is often associated with the automobile industry, although it is also utilized for other consumer products. Demarcation zones are also commonly defined in refinishing paint work between damaged and non-damaged areas of a workpiece. It is advantageous to provide a definite demarcation zone at and along the edge of the damaged area, even though this area is to be repainted the same color as the non-damaged area.
Various apparatus are known in the art for selectively dispensing masking tape as well as and other adhesive tapes, labels and strips. In the most basic of these prior apparatus, a roll of masking tape is mounted on a hub or spindle. The apparatus supports the hub as well as a cutting edge for cutting the tape into desired lengths. The masking tape is usually quite narrow when compared with the area to be protected from overspraying. Accordingly, to mask larger areas, apparatus or devices have been developed which dispense a continuous sheet of masking paper along with a strip of conventional masking tape affixed to one side edge thereof.
A particular drawback to this type of system is that paint tends to form a ridge along the edge of the masking tape. Removal of this objectionable ridge necessitates additional finishing steps.
Through the years, various attempts have been made in an effort to improve paint masking systems such that these additional finishing steps could be eliminated or at least reduced. Generally, these systems have required the use of special masking tapes. For example, one system uses a non-metallic tape which has an adhesively backed portion and a nonadhesively backed portion. The tape is folded longitudinally between the adhesive and nonadhesively backed portions such that the nonadhesive portion flares outward. The tape is applied to a workpiece so that the flared portion forms a tapered pocket along the demarcation zone which generates a a feathered paint edge thereat during painting. The resilient memory of the tape and buckling characteristics of the nonadhesive portion when the tape follows a curved demarcation line tend to cause variations in the feathered or tapered pocket, hence variations in the tapered paint edge. The quality of the work product achieved in using this system is directly related, in large part, to the skill of the painter.
An improved paint masking system is illustrated in the commonly assigned U.S. patent application Ser. No. 165,616, filed July 3, 1980. The masking system of this application provides a feathered paint edge at the demarcation zone and is comprised of a layered structure. The layered structure includes a mask layer having one surface coated with adhesive defining an adhesive layer, a mask section adhered longitudinally along a portion of the adhesive layer, and a release strip adhered longitudinally along the remaining portion of the adhesive layer. In use, the release strip is removed so that the mask may be adhesively secured to the mask along some desired demarcation zone. A pressing type force is applied to the mask along the demaraction zone for causing the mask section to diverge outwardly of the workpiece. During painting, a portion of the paint spray migrates into the pocket-like area thus formed to generate a feathered paint edge. When this masking system takes the form of a tape having some indefinite length, removing the release strip and thereafter positioning the tape on the workpiece becomes an awkward and difficult manual manipulation. In this form of the system, some type of dispensing apparatus or device is desirably employed.
To that end, a number of structures have heretofore been available for feeding or dispensing layered tapes and/or labels. However, several problems contribute to the failure of these dispensers in finding ready utility in the painting industry, particularly for the new system described above. For example, none of these prior dispensers are adapted for use in conjunction with a masking paper feeder and none are adapted to readily accommodate the changing and/or replacement of tape rolls. Rather, changing of the rolls typically requires disassembly of the hub assembly as well as other cumbersome manipulations. Further, the tape roll brakes included on some prior dispensers are difficult to maintain and require constant adjustment.
The present invention contemplates apparatus which overcomes the foregoing problems and provides a new and improved layered tape and painting mask dispensing apparatus which is simple in design, easy to use and readily adapted to use in a wide variety of applications or environments.